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COMPRESSION – THE RESEARCH CONTINUES
Dom Cadden
Commonwealth Champion Powerlifter
The use of compression in medical garments goes back a long way, but its application for sports is relatively much newer. Consequently, research is constantly being undertaken to verify exactly what assistance compression garments can offer in a variety of different conditions and activities. Here’s what recent research findings and guidelines from sporting bodies around the world have to say.
WHAT DEFINES A ‘COMPRESSION GARMENT’?
First up, it’s best to clarify exactly what we mean by 'compression garments'. The Australian Sporting Goods Association (ASGA) points out that while a tight LYCRA® garment might look and even feel (at first) very similar to a ‘compression’ garment, but there’s more than meets the eye. A real compression garment has ‘graded compression’ – that is, the compression exerted differs over a given distance. In a pair of tights, for example, this means the compression at the ankle and calf is higher than at the thigh, which facilitates the flow of blood through the deep veins back towards the heart. 2XU Compression, unlike most other compression garments, uses a 360° circular knit, which means the weave’s stretch and compression is the same no matter which direction it is pulled.
HEATING AND COOLING
The ASGA quotes tests that show that due to the evaporative cooling and prevention of moisture build-up that tends to occur thanks to the composition of the fabric used, compression garments can reduce the surface temperature of the body by 3°C. So while the garments accelerate the warm-up of cold muscles, they are also particularly cooling during exercise.
REDUCING MUSCLE DAMAGE AFTER HIGH INTENSITY EXERCISE
Muscle damage is an inevitable after high intensity exercise, but anything that can reduce this is a big leg-up to recovery and repeat performance. A British study of elite Rugby Union players reported that compression garments worn immediately after a rugby match significantly reduced markers of muscle damage (creatine kinase) compared to passive recovery at 36 and 84 hours post-match.
RECOVERY FOR ULTRA-ENDURANCE
Sports physiology professor Elmarie Terblanche (Stellenbosch University, South Africa) wasn’t sure how much to believe the findings of the many studies on compression that took place in the lab. So she conducted the first real-world study, following athletes running the Two Oceans ultra-race in South Africa. What she found was that the athletes who raced in compression socks versus those in regular knee-high socks or those without either, had significantly less muscle damage and were able to recover more quickly, with some even ready to train again three days later. Those wearing the socks also ran on average of 12 minutes faster.
“Considering that they ran one of the most difficult ultras in South Africa, this was significant,” she said.
Terblanche recommends that athletes wear the socks for long sessions and for the 24 hours following. While she acknowledges her study can’t be considered conclusive, because there’s always a chance for a placebo effect in the real world scenario, the recovery findings are in line with other research.
SHORT-TERM RECOVERY IN THE WELL-TRAINED
A study Lincoln University study (New Zealand) took 22 well-trained male rugby union players and put them in either a full-leg compression tights or a similar-looking non-compressive placebo to wear continuously for 24 hours after performing a series of circuits developed to simulate a rugby game. After the 24-hour recovery, garments were removed and they did 10 x 40m sprints at 30-second intervals, followed 10 minutes later by a 3km run. One week later, the groups were reversed and testing repeated.
When wearing the compression tights, times for the 3km run decreased, average sprint times improved and fatigue was diminished during the repeated sprint test. On top of all this, 48 hours after testing the delayed onset muscle soreness was substantially lower in the compression group compared with the placebo group.
ACTIVE RECOVERY FROM SPRINTS
This was a similar study to the one above, but it examined the effect of wearing compression tights during 6 x 5-minute runs at different speeds for each stage, with 30 seconds of “rest” in between stages (actually, a blood sample was taken for testing during each “rest”). The tests, conducted through Bond University, used 25 semi-professional rugby league players who wore compression tights or running shorts (each player did the test twice, once in short, once in compression gear).
The results indicated that the compression tights seemed to help the active recovery process by reducing blood lactate concentration and heart rate, which the authors concluded “has important consequences for many sports that are intermittent in nature and consist of repeated bouts of high-intensity exercise interspersed with periods of low-intensity exercise or recovery”.
ANYBODY JUMP?
An assessment of studies examining the effect of compression clothing on endurance, strength and power, motor control and several parameters during or after exercise. The assessment, published in the International Journal of Sports Physiology and Performance, concluded that “that there are beneficial effects of compression clothing, especially during intermittent high-intensity exercise such as repeated sprinting and jumping, rather than during submaximal endurance exercise.”
Researchers concluded that compression clothing works best when it is applied for recovery purposes 12 to 48 hours after significant amounts of muscle-damage-inducing exercise, “small or moderate effects for recovery after maximal strength and power, reductions in muscle swelling and perceived muscle pain, and blood lactate removal. Researchers noted large effects for managing body temperature and recovery for activities involving vertical jumping.
IS YOUR COMPRESSION THE RIGHT FIT?
A meta-analysis of studies on the use of compression garments for recovery (published in the British Journal of Sports Medicine) highlighted the fact that commercially available compression garments are usually fitted using a generalised sizing system. Lead author Jessica Hill from St Mary’s University College wrote that the shape of your body or the wrong choice of size is likely to affect the degree of pressure exerted by the garment, which will then have a direct impact on the ability of the garment to reduce the effects of exercise-induced muscle damage. Hill commented that the majority of published studies didn’t measure the degree of pressure exerted by the garments. This, she felt, meant it was possible that a number of subjects wore garments that simply weren’t tight enough to deliver the potential benefits, which would explain the variation among study findings.
At 2XU, compression garments are engineered according to measurements taken by a 3D Body Scanner using white light technology to produce a true-to-scale 3D body map. This allows the fit and sizing of the compression gear to be based on the scans of hundreds of individuals of various shapes and sizes. You can see that the sizing chart also allows for a generous crossover of heights and weights between sizes so that no body type or shape ‘falls between the cracks’.
2XU Compression has been tested at both the fabric and garment level to evaluate the fabric power and its gradient pressure through a research project at RMIT University. A Salzmann Pressure Measuring device (widely recognised and used in the medical compression industry) was used for quality control purposes and to ensure correct pressure ratings are achieved for graduated compression apparel. So even though the pressure is dependent on the individual’s limb measurements, it’s always graduated from ankle to thigh then hip through the combination of fabrics used and the fit.